In Defense of Geometry: Part II

In my last post, I complained about the shrinkage of geometry, a decades-long trend in US math education. Some of the reasons I suggested for this state of affairs is the offering of a substantial amount of algebra to a much broader population, the growth of calculus as a high school subject, and the increasing place given to… Continue reading In Defense of Geometry: Part II

Transformational Proof

Prior to the publication of the Common Core State Standards for Math (CCSSM), transformational geometry was rarely seen in geometry courses. It certainly was missing from the one I taught. Still, I have always been interested in this topic, and it provided the backbone of my "Geometry 2" class, a post-Algebra 2 elective which I… Continue reading Transformational Proof

Time and Tide

This is my yearly report on the Asilomar conference of the California Math Council, Northern Section. Because I was presenting three times, I didn't end up attending as many sessions as I would have liked. As always at Asilomar, I enjoyed hanging out with my ex-colleagues, running into friends, and meeting the occasional fan of… Continue reading Time and Tide

Upcoming presentations

I have a bunch of presentations coming up. That will be your last chance to hear me for a while, as my NCTM San Antonio talk was rejected†. Who knows, maybe retirement will finally kick in!Online Webinar: Reaching the Full RangeAs everyone knows, students learn math at different rates. What should we do about it?… Continue reading Upcoming presentations


In between June 27 and August 4, 2016, I presented seven to ten workshops (depending on how you count) ranging from a couple of hours to four days. I share most of the handouts, resources, and slides on my Summer Workshops site. (See below my signature for more details on what's there.)The site will remain… Continue reading Eclectic

NCTM Is Its Members

This post's title was also the subject of an e-mail from Matt Larson, the new President of NCTM sent to the membership. You can read it here. Since he asked for suggestions, I replied to his message. Here is what I wrote, slightly expanded.--Henri --------------------------------------------------------------------- Dear Matt Larson,I’ve been a member of NCTM for who… Continue reading NCTM Is Its Members

Hoping to see you soon!

Here is a list of my upcoming appearances, ranging from 20 minutes to a full week. Perhaps you can attend one of them!NCTM National Meeting in San FranciscoA Hands-on Approach to Operations and Equivalent Expressions  Thursday 14 April, 8:00-9:15am. 3022 Moscone WestThis is a hands-on Lab Gear workshop aimed at grades 6 to 8. The… Continue reading Hoping to see you soon!

Visual Algebra

I will be teaching two instances of my Visual Algebra workshop this summer: grades 7-11, June 27-30, in Oakland; and grades 6-9, July 25-27, in Saint Louis. (More info). This is probably the topic I have presented the most often in the last 25 years.To many students, not to mention teachers, parents, and administrators, algebra… Continue reading Visual Algebra